SQL 表分组后取各个分组的第一条数据

SELECT ROW_NUMBER()OVER(PARTITION By GroupId  ORDER BY GroupId ) CN, * FROM T_DIM_SENSOR_GROUP

 

 

 

 

 

 

select * from (

SELECT ROW_NUMBER()OVER(PARTITION By GroupId ORDER BY GroupId ) Cu, * FROM T_DIM_SENSOR_GROUP
) t where t.Cu<2